The early upgrade of the Londonderry to Coleraine train line has been agreed by the Executive.
A total of £27 million of secured funding allows the rail relay to start next July.
Transport company Translink aims to complete the first phase of the relay, from Coleraine to Castlerock and from Eglinton to Londonderry, by April 2013, during the city's year as UK City of Culture.
The line will be closed for approximately nine months.
Regional Development Minister Danny Kennedy said: "This announcement secures the Londonderry to Coleraine rail line's future."
There will be eight trains per day for most of the City of Culture year.
Mr Kennedy added: "Importantly, it sends out a clear message that the Executive is determined to ensure that opportunities arising from potential cultural, tourism and sporting events will be fully supported."
The completion of the first phase would allow eight return services a day until signalling work can start in 2014-15.
The minister said: "Translink will bring forward a phased upgrade of the Londonderry rail line which will start in July 2012. This is two years before the original plans set out in this budget period and in time for the major events planned for the City of Culture 2013."
Sinn Fein assembly member Raymond McCartney welcomed the decision, and said: "This development will give added confidence to those tasked with planning for the City of Culture 2013 and other events over the coming years. This is another example of what can be achieved if we have clear goals and persistence."